There is more to Web Design than just creating a design that is fresh and appealing. A website needs to be intuitive for users.
Web Development is a broad term for any activities related to developing a website. It ranges from designing to programming.
SEO is the process of improving the volume and quality of traffic to a web site from search engines such as Google and Bing.
A web hosting is a type of Internet hosting service that allows people to make their website accessible via the World Wide Web.